CYST/BULLA/BLEB

                             Bleb                             Bulla                                         Cyst

Site : Within visceral pleura             Arises within secondary lobule        Lung parenchyma or mediastinum

Size  :          1–2 cm                              1 cm to 75% of a lung                                     2–10 cm

Lining :Elastic laminae of  pleura        Connective tissue septa                             Epithelium

Associated: Spontaneous pneumothorax     Bronchogenic carcinoma                  Respiratory infection

condition

BULLA:

A bulla is an air-containing space within the lung parenchyma that

arises from destruction, dilatation, and confluence of airspaces

distal to terminal bronchioles and is larger than 1 cm in diameter

BLEB:

A bleb is an accumulation of air between the two layers of the

visceral pleura that arises when the thin covering of the bleb ruptures

and permits entry of air.

CYST:

Cysts are epithelial-lined cavities that may resemble bullae on radiographs

(FISHMAN)